On Thu, Nov 10, 2022 at 04:03:46PM +0100, Aldy Hernandez wrote:
> [Jakub, how's this? Do you agree?]
>
> After further reading of the IEEE 754 standard, it has become clear
> that there are no guarantees with regards to the sign of a NAN when it
> comes to any operation other than copy, copysign, abs, and negate.
>
> Currently, set_nonnegative() is only used in one place in ranger
> applicable to floating point values, when expanding unknown calls.
> Since we already specially handle copy, copysign, abs, and negate, all
> the calls to set_nonnegative() must be NAN-sign agnostic.
>
> The cleanest solution is to leave the sign unspecificied in
> frange::set_nonnegative(). Any special case, must be handled by the
> caller.
>
> gcc/ChangeLog:
>
> * value-range.cc (frange::set_nonnegative): Remove NAN sign handling.
> (range_tests_signed_zeros): Adjust test.
LGTM, thanks.
Jakub
